In recent years, there has been proposed an illumination device using an organic electroluminescence element (surface light emission panel). In a case where it is necessary to increase a size of the illumination device, it may be achieved by increasing a size of the surface light emission panel. This, however, may lead to problems such as increased size of a manufacturing apparatus and a lower yield rate. Accordingly, in WO 2013/146764 A (Patent Literature 1), the size of the illumination device is increased by arranging a plurality of surface light emission panels, each having a size easy to be manufactured, in a plane.